Old HP Logic Analyser Pods

[dexters_lab]

I have some pics some of you might be interested in, they are of the probe adaptor from a HP Logic Analyser model 1630G from circa 1985. Originally there was total 8 pods that each provided the interface from the probe clips to the analyser itself.

They proved to be the most interesting thing in it, so thought i'd share.

It's a ceramic pcb, with multiple layers including laser trimmed resistors and several cob devices hidden under a ceramic enclosure.

[dexters_lab]

more pics...

[Mark_O]

Wow.  That is pretty interesting.  Thanks for the high-rez peeks.

[marshallh]

Awesome pics, thanks for sharing

[dexters_lab]

No worries, figured someone would like to see

[SeanB]

Front end is a big ASIC and a built in precision power supply for it, voltage reference, opamp and power device all there with some precision trimmed resistors.

[amyk]

Was it dead?

[dexters_lab]

Was it dead?

No, i believe it was working when i bought it

[TiN]

Thanks for pics, nice to see such stuff on web.

Here's my Tek P6810 probe tip photo:

[dexters_lab]

Front end is a big ASIC and a built in precision power supply for it, voltage reference, opamp and power device all there with some precision trimmed resistors.

Thanks Sean

Cables from the pod to the analyzer are twisted pairs so guess then asic is also a differential driver?

[dexters_lab]

Thanks for pics, nice to see such stuff on web.

Here's my Tek P6810 probe tip photo:

Lol, you are brave! Just looked at the price of those

[codeboy2k]

Black magic, thy name is HP!

Great pics, thanks for sharing !

If I'm not mistaken, there are some precision trimmed caps on there too.

What kind of process is that, where they seem to screen-print the traces, the resistors and some kind of insulating bridges and also the dielectric for the capacitors?  Does anyone know?

You can see where they built it with the RC network shorted out by fused links, probably used the ATE to first test that it had continuity from the board to the probes, then zapped all the fuses, and trimmed the RC network for each probe tip using some test signals for maximum bandwidth. 

oldskool HP Voodoo Magic, I say

[edavid]

What kind of process is that, where they seem to screen-print the traces, the resistors and some kind of insulating bridges and also the dielectric for the capacitors?  Does anyone know?

It's called a thick film hybrid (but that Wikipedia article isn't very good, look at some other sources).

It's an old, low tech, but fairly high cost technology.  Even my not very well equipped alma mater had a hybrid lab.

[codeboy2k]

It's called a thick film hybrid (but that Wikipedia article isn't very good, look at some other sources).

It's an old, low tech, but fairly high cost technology.  Even my not very well equipped alma mater had a hybrid lab.

Thanks! I'll dig up some more on it to satisfy my curiosity.. My alma mater had a VLSI lab, probably had a hybrid lab too, but I never went down that path and into those labs.  What fun I missed ...

EDIT: found an informative page here:
http://www.ami.ac.uk/courses/topics/0255_tft/